Genetic profiling as a marker for risk of sudden cardiac death.

PURPOSE OF REVIEW: Clinical trials provide evidence that an empirical approach of implantable cardioverter-defibrillator implantation in all heart failure patients (ejection fraction
RECENT FINDINGS: Through the past 10 years of primary prevention implantable cardioverter-defibrillator trials, the number of patients needed to treat to prevent a sudden death has risen from one in four patients to one in 14. Although numerous clinical tests exist for stratification, they are of low positive predictive value in assessing arrhythmic risk, and have not been prospectively validated as effective strategies in identifying arrhythmia-prone patients. Recent data from genetic studies identifying genes responsible for sudden cardiac death have compiled a list of relatively common genetic variations (polymorphisms). These polymorphisms, encoding for proteins known to be involved in cardiac electrophysiology, may contribute to arrhythmic risk in the milieu of heart failure.

SUMMARY: Current clinical indications for implantable cardioverter-defibrillator implantation in primary prophylaxis of sudden cardiac death necessarily include a significant number of patients who may not benefit. The identification of common genetic variations causing an increased risk of vulnerability to ventricular arrhythmia in heart failure patients may optimize the use of medical resources through rapid identification of sub-populations at highest risk.